Membrane catalytic heater

ABSTRACT

A portable catalytic combustion heater, wherein fuel vapor ( 11 ) and air ( 10 ) are supplied to a catalyst ( 6 ) which promotes the flameless combustion of fuel and releases that. The fuel is supplied as a liquid, passes through a selectively permeable membrane ( 8 ) such as fuel vapor exits the membrane and is fed to the catalyst ( 6 ). Additional features include porous supports and means of enhancing and diminishing the catalytic rate of combustion and controlling the heat output.

BACKGROUND OF THE INVENTION

Flameless combustion heaters are well known. They typically work on theprinciple that an appropriate hydrocarbon-based fuel, when in contactwith a suitable catalyst in the presence of air (or oxygen), willundergo combustion and release heat. This heat can then be distributedand used for a variety of purposes.

A variety of patents describe the incorporation of such a device on agarment such as a jacket or a belt for providing heat to the body. Theytypically describe means of pumping the fuel, preheating the fuel-airmixture (often by ignition), and controlling the feeding of the mixtureto a catalytic area and distribution of heat resulting from thereaction. These systems tend to add a lot of complexity and cost to theproducts to which they are incorporated.

Furthermore, these patents describe heaters which are often based onalkane fuels, preferably propane or butane. These fuels are gases, andas such do not lend themselves to being carried easily in portableapplications including garments. When using liquid alcohols as fuels,the fuel-air mixture is preheated and ignited before catalyticcombustion occurs. Fuels in this category include methanol, naphtha, andethanol. It is advantageous to react them in the gas phase with air inthe presence of a catalyst. Since alcohols are liquids under operatingconditions, one way to achieve this goal is shown in U.S. Pat. No.6,062,210, which describes means of feeding methanol fuel through poresplaced in a feeding tube in close proximity to the catalyst. However,this method is not selective, in that the pores will also allow thepassage of other substances, which may happen to be present with themethanol fuel. This method can also allow the passage of liquid fuel toflood the catalyst.

These and other shortcomings are overcome in the invention describedherein.

SUMMARY OF THE INVENTION

The invention described herein refers to a portable catalytic heater inwhich fuel vapor and air (or other means of oxygen supply), are suppliedto a catalyst. The catalyst promotes the flameless combustion of thefuel releasing heat. The liquid fuel is supplied through the use of aselectively permeable membrane, such that only the fuel vapors diffusethrough the membrane and are fed to the catalyst. The catalyst is placedon a support that allows for the diffusion and mixing of reactants suchas a porous fiber felt coated with catalysts. Alternatively, theselectively permeable membrane may support the catalyst. The supply offuel to the selectively permeable membrane and the exact identity of themembrane serve as a way to regulate the degree of heating provided bythe catalytic heater. The selective molecular filtration of the fuelthrough the membrane keeps the catalytic heater from being contaminatedfrom impurities in the fuel, such as salts. The selective permeabilityof the membrane to fuels (e.g. methanol), over the product (i.e. water),keeps the liquid fuel reservoir from being contaminated with the productand maintains the fuel concentration and a steady rate of fuel delivery.By containing the fuel behind the selective membrane and using diffusionto deliver the fuel, the rate is dependent upon the concentration ofliquid in contact with the fuel membrane rather than the fuel vaporpressure. This makes the delivery of fuel and air to the catalyst lesssensitive to temperature.

Another feature of the invention is an additional coating which protectsthe combustion catalyst from contamination and can enhance the catalyticeffects. If the coating has the ability to conduct ions (i.e. protons),it may be used to enhance or lower the catalytic combustion rate throughelectrochemical processes on the catalysts (removal/addition ofhydrogen/proton intermediates to catalytic surface). This may beachieved by inserting two electrodes on either side of the coating andapplying a voltage across said coating. The coating also has certainpermeability to the fuel and the products of the combustion reaction. Itserves the purpose of adhering the catalyst powders to the substrate onwhich they are supported and can limit the catalytic combustion rateserving as yet another regulating mechanism in our invention. Thecoating can also have an affinity for the fuel, oxidizer, and productsto increase the effectiveness of the fuel. The catalytic heater can beincorporated into a system for various applications. One of the uniquefeatures of using a liquid fuel with the selectively permeable membranein proximity to the catalytic heater is when the fuel reaches itsboiling point it removes heat from the catalytic reaction site andsubsequently limits the maximum temperature. The vaporized fuel can becondensed in a heat exchanger and deliver the thermal output of theheater efficiently. Different mixtures of fuels or a maximum pressure ofthe fuel reservoir can be chosen to set the boiling point of the fueland hence the maximum temperature of the heater. This fuel boilingmechanism along with the back diffusion of carbon dioxide and nitrogencan also be used to keep the fuel homogeneous and self purging. Bykeeping the fuel homogeneous and not in direct contact with catalyststhe heater can easily be purged of fuel contamination by draining thefuel.

Another feature of this invention is the membrane through which the fuelis fed is not prone to failure. Unlike U.S. Pat. No. 6,138,665 where thefuel flows through porous tubes, our invention describes the use of amembrane that works by diffusion. One practical way in which thisfeature is important is the ability to run a catalytic heater with puremethanol fuel, and no water added.

Yet another feature of this invention, due to the fueling mechanism ofusing the selectively permeable membrane, is that the catalytic heateris insensitive to orientation. A steady delivery of liquid fuel or gasfuel is needed to maintain contact with the selectively permeablemembrane. Bubbles and gas pockets in the fuel will not significantlyeffect the diffusion of fuel through the selectively permeable membraneas long as the surface of the membrane is wetted by fuel. A wet coatingor wicking material could be used to spread liquid fuel uniformly overthe surface of the selectively permeable membranes. Increasing thehydraulic pressure will not significantly increase the concentration ofa liquid fuel against a selectively permeable membrane. Thus thediffusion rate of fuel will not be changed if the system is invertedcausing a low or high hydraulic pressure on the selectively permeablemembrane. This invention also does not depend on the use of pumps whichadd complexity and cost of the heater, to create a fuel oxidizermixture.

Additional features of this invention are the pressurization of the fuelbehind the selectively permeable membrane and its flexibility whichenable unique passive controls of the diffusion of fuel and air.Temperature selective diffusion through the membrane can also be used tolimit or accelerate the fuel delivery. Also, the flexibility of thepolymers and rubber materials used in this invention permits flexibilityin packaging into a wide variety of applications such as apparel,blankets, machinery, dwellings, shipping containers, storage containers,insect attractants, humidifiers, and perfume generators.

Prior Art

Weiss U.S. Pat. No. 2,764,969 “Heating Device”. This patent describes acatalytic heating system comprising a plurality of tubes which directthe heat generated from the reaction to different parts of the user'sbody. It does not describe means of using a selectively permeablemembrane.

Bals et al. U.S. Pat. No. 5,331,845 “Probe and Method for DetectingAlcohol”. This patent describes a probe for measuring the concentrationof an alcohol. The probe has a membrane that is permeable for vapors ofthe alcohol but substantially impermeable for the liquid. It does notteach the application of the system to a catalytic combustion heater.

Welles U.S. Pat. No. 5,901,698 “Mechanically Compliant and PortableCatalytic Heating Device”. This patent describes a portable catalyticheater where reactants are uniformly released through porous tubes wovenwith catalyst-impregnated glass filaments into a sheet-shaped,fabric-like structure enclosed in a Mylar envelope. It does not describethe use of membrane materials that are selectively permeable.

Yates and Yates U.S. Pat. No. 5,928,275 “Body Warmer Belt”. This patentdescribes a heater system in the shape of a belt for warming the user'skidney region. It uses a heating pouch made up of activated charcoal,iron powder, and saltwater and wood fibers. It does not cover means ofregulating the amount of heat using permeable membranes, and it does notteach how to turn the device off.

Welles U.S. Pat. No. 6,062,210 “Portable Heat Generating Device”. Thispatent describes a portable catalytic heater where reactants aredirected through channels contained within a thin, flexible elastomericsheet of material. The catalytic heat elements are disposed within saidchannels. It does not describe the use of membrane materials that areselectively permeable.

Hanada et al. U.S. Pat. No. 6,138,664 “Warming Jacket”. This patentdescribes a catalytic heater incorporated onto a jacket to providewarmth for a user's body. It does not describe the use of selectivelypermeable membrane materials.

Welles U.S. Pat. No. 6,138,665 “Portable Heat Generating Device”. Thispatent describes a portable catalytic heater where reactants areuniformly released through porous tubes woven with catalyst-impregnatedglass filaments into a sheet-shaped, fabric-like structure enclosed in aMylar envelope. It does not describe the use of selectively permeablemembrane materials.

Hanada et al. U.S. Pat. No. 6,206,909 B1 “Portable Warmer Suitable for aBody”. This patent describes a portable catalytic heater incorporatedonto a belt that is used to warm the user's body. It does not describethe use of selectively permeable membranes.

Trade Names/Materials:

Silicone rubber membranes

Specialty Silicone Products Corporate Technology Park

3 McCrea hill Road

Ballston Spa, N.Y. 12020

DAIS polymer electrolyte (DAC589-9.1% solid solution)

DAIS-Analytic Corp. 11552 Prosperous Dr. Odessa, Fla. 33556

Zylon felt

Toyobo 2-8, Dojima Hama 2-Chome, Kita-ku Osaka, 530-8230, Japan

Pt/Ru black catalyst on Carbon

Alfa-Aesar 30 Bond Street Ward Hill, Mass. 01835-8099 Cool Max DuPontCorporation 1007 Market Street Wilmington, Del. 19898 Engelhard ChemicalCatalysts Group 554 Engelhard Dr. Seneca, S.C. 29678 Nafion:Perfluorosulfonic Acid, DuPont Corporation.

Alcohol solutions available through:

Solutions Technology, Inc., P.O. Box 171 Mendenhall, Pa. 19357. AldrichChemical Company P.O. Box 2060 Milwaukee Wis. 53201

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Cross-sectional view of the fuel tank with membrane and feltsupported catalyst.

FIG. 2. Cross-sectional view of the fuel tank with membrane and catalystembalmed in matrix and an outer diffusion membrane.

FIG. 3. Cross-sectional view of a selectively permeable tube fueldelivery and a surrounding tubular catalyst supporting nonwoven fabric.

FIG. 4. Cross-sectional view of a tube fuel and air delivery to anenclosed tubular catalyst supporting felt or nonwoven fabric.

FIG. 5. Cross-sectional view of the fuel tank with membrane heater andthermopile and heat exchanger surfaces.

FIG. 6. Cross-sectional view of the catalytic heater system withthermopile, valves, fans, regulating electronic thermostat and gas flowchannels.

FIG. 7. Schematic representation of the electrical control system forthe catalytic heater system.

FIG. 8. Cross-sectional view of the catalytic heater electrochemicalcell and diffusion fuel feed.

FIG. 9. Cross-sectional view of the catalytic heater with heatingregulation with membrane valving.

FIG. 10. Cross-sectional view of the catalytic heater configured with aselectively permeable sealed fuel ampoule.

FIG. 11. Cross-sectional view of a selectively permeable fuel ampoulewith a fuel impermeable container.

FIG. 12. Cross-sectional view of the catalytic heater configured with apump ampoule.

DETAILED DESCRIPTION OF TEE PREFERRED EMBODIMENTS

In FIG. 1 a fuel tank 10 is shown filled with methanol fuel 11. Thealuminum tank 10 has a silicone rubber membrane 8 (Specialty SiliconeProducts, Corporate Technology Park, 3 McCrea Hill Road, Ballston Spa,N.Y. 12020) sealed to the tank wall with 100% silicone rubber sealant(GE Silicones, Waterford, N.Y. 12188); The methanol fuel 11preferentially diffuses through the silicone rubber membrane 8 to mixwith air 12. Several alternative fuels 11 are formaldehyde, formic acid,1,3,5-trioxane, di-methyl-ether, acetone and pentane, among others. Afelt of polybenzoxazol (PBO), a high temperature high performance fiber5 (Zylon felt, Toyobo, 2-8, Dojima Hama 2-Chome, Kita-Ku, Osaka,530-8230, Japan) is coated with Platinum and Ruthenium (Pt/Ru) blackcatalyst 6 (Alfa-Aesar Alfa-Aesar 30 Bond Street Ward Hill, Mass.01835-8099). Alternative felts are made of fibers of polybenzimidazole(PBI), polyimides, alumina, fiber glass, zirconia, quartz, p-aramidsfelts. This catalyst layer is then over-coated with a thin coating 7such as a solid polymer electrolyte DAIS (DAIS-Analytic Corp., 11552Prosperous Dr., Odessa, Fla. 33556), Nafion (Solution Technology, Inc.,Mendenhall, Pa. 19357) or silicone rubber. The example coatings andmaterials can be deposited by airbrush spraying a suspension of thecatalyst powders. Over-coatings can be deposited by airbrush spraying ofa solid polymer electrolyte dissolved in a solvent and dried under airor inert gas. In operation air and fuel diffuse into the coated felt 5and catalytic combustion occurs on the surface of the catalyst Pt/Rublack. The felt 5 provides a substrate resistant to high temperaturesand with a low heat capacity. The catalyst 6 breaks down the methanoland oxidizes it with oxygen from the air. Specific catalysts used arethose that can oxidize hydrocarbons and carbon monoxide, which is thelast step in the catalytic combustion process. The overcoat 7 on thecatalyst serves the purposes of protecting and adhering the catalystpowders and coatings to the felt 5. It also has a high solubility andaffinity for the fuel and water so it increases the concentration of thefuel on the catalyst 6. The overcoat 7 also has a high but limitedpermeability to fuel and oxygen, which limits the rates of catalyticcombustion on the catalyst surface and keeps the catalyst from goinginto high temperature or flame combustion. High temperature combustioncan damage the components. The selective permeability of the coating 7on the catalyst may protect the catalyst by keeping large organicmolecules and salts from reaching the surface of the catalyst 6 andlimit the presence of products such as water on the catalyst surface,protecting the catalyst surface from environmental contamination.Coatings 7 on the catalysts such as Nafion or DIAS that are electrolyticmay enhance the catalytic oxidation. The coating 7 on the surface of thecatalyst 6 can also have a permeability that changes with temperature toact as a fuel and oxidizer moderator. As an example, materials such asthe solid polymer electrolytes, (e.g. Nafion and DAIS) have lowermethanol permeability when they dehydrate with increasing temperature.The catalyzed felt 3 catalytically burns the methanol and air mixture asthe oxygen 12 diffuses from the surrounding air and the methanoldiffuses through the selectively permeable membrane 8. The selectivepermeability of the membrane 8 prevents water from diluting the fuel andreducing the fuel delivery rate. It also filters many contaminates thatcould be in the fuel from reaching the catalysts 6. The selectivediffusion through membranes is dominated by the concentration gradientacross them and its permeability at particular temperatures. The fueldelivery is therefore independent of the vapor pressure of the fuel whenthe selective membrane is immersed in fuel. The heat produced by thecatalyst felt 3 is conducted into the aluminum fuel tank 10 and into thealuminum cover wall 4. The heat can be conducted and distributed to theapplication through these surfaces. Heat can also be moved by vaporizingand condensing the fuel such as methanol from the fuel tank 10 to thevent line 2. Fuel 11 such as methanol will condense in the vent line 2and be returned to the fuel tank 10 by gravity. The carbon dioxideproduced in the catalytic burner exhausts through the inlet diffusionroute 12 or through the silicone membrane 8. When the heater is running,the temperature can get above the boiling point of the fuel and it willboil. The fuel vapor goes up the vent line 2 and condenses on the wallsof the vent line 2. This boiling of the fuel acts to limit thetemperature of the heater 3 by heat removal with the vaporized fuel 9.The dissolved carbon dioxide in the fuel is also removed from the fuelby boiling 9 of the fuel 11 and vented 1 out of the vent line 2.

In FIG. 2, the heater is composed of catalyst particles 13 incorporatedinto a material such as silicone rubber, Nafion, or DAIS or otherselectively permeable embalming material 21. The catalyst particles 13can consist of a thin film of platinum and ruthenium (Pt/Ru) catalyst oratomic catalyst clusters of platinum (Pt) 23 dispersed over the surfaceof a high surface area zeolite, alumina, or activated carbon particles22. In this design the fuel diffuses through the selectively permeablemembrane 18, through the embalming material 21 to the catalyst particles13. Oxygen diffuses from the air 15 through an outer membrane made ofsilicone rubber or a porous filter to dust and liquid water such asmicro-porous polytetrafluro ethylene 14 (DuPont Corporation, 1007 MarketStreet, Wilmington, Del. 19898), or Nafion: Perfluorosulfonic Acid,(DuPont Corporation). Alcohol solutions of Nafion are available through:Solutions Technology, Inc., P.O. Box 171, Mendenhall, Pa. 19357.,Wilmington, Del. Over this outer membrane 14 perfluoropolyalkyleneoxides such as polyperfluropropylene oxide or polyperfluoropropyleneoxide co-perfluroformaldehyde, (Aldrich Chemical Company. P.O. Box 2060Milwaukee Wis. 53201) can be coated to give it more selectivepermeability to oxygen and selectively retain fuel. The oxygen membranecan also be a material or mechanical mechanism that increases ordecreases its rate of oxygen diffusion depending on temperature, thuslimiting the catalytic combustion. The outer membrane 14 can also be amaterial or mechanical mechanism that changes its thermal insulationproperties so that at low temperatures it is a good insulator and athigher temperatures it is a heat transfer material. A micro-porousmaterial such as expanded polytetrafluoroethylene (PTFE),polybenzimidazole (PBI) felt or perforated polyimide sheet could also beeffective in creating a diffusion filter and thermal insulation region14 between the catalyst 13 and the outside air 15. The oxygen diffusesto the surface of the catalyst particles 13 to react with the fuel onthe catalyst 23. The heat generated by the catalytic combustion isconducted into the fuel tank and to the outer surface of the air filter14. The heat can be delivered to the application through the case 20(made of aluminum, PVC or stainless steel), the condensation tube 17 orthe surface of the air membrane 14. The methanol fuel 21 will boil whenit reaches its boiling point and remove heat from the surface of thefuel membrane 18. Water and carbon dioxide produced by combustion at thecatalyst 13 will diffuse through the embalming material and the fuelmembrane 18 and out through the air membrane 14. The selectivepermeability of fuel over water of the fuel membrane 18 compared to theair membrane 14 will lead to the water product being blocked fromdiffusing into the fuel 21 and the dominant water exhaust route beingout through the outer membrane 14. The silicone rubber, Nafion and DAISmaterials will all have a high permeability to carbon dioxide. A largefraction of the product carbon dioxide will diffuse through the fuelmembrane 18 and into the fuel 21. Along with the heat removal by boilingthe fuel 19 and condensing 78 on the outlet tubes 17, carbon dioxide isvented 16 from the fuel with the boiling methanol 19. The condensedmethanol 78 in the outlet tube 17 is returned to the fuel tank viagravitational pull. This device just described with the addition of afueling scheme could be used as a pocket heater in apparel.

In FIG. 3 the methanol fuel 26 is contained in a silicone rubber tube 28lined with a polyester fiber wetting tube liner 33 made of Cool MaxÔ (DuPont). The silicone rubber tubing 28 is surrounded by cylindrical porousfelt of PBO or nonwoven fabric 31 that is coated with catalyst 30. Thecatalyst-coated felt tube 31 is then surrounded by an uncoated PBOnonwoven fabric 29. In operation the methanol fuel 26 diffuses throughthe wall of the silicone rubber tube 28 and out to the catalystparticles 30. Oxygen diffuses from the atmosphere 27 through the outerPBO nonwoven fabric 29. Heat from the catalytic combustion is conductedthrough the outer PBO nonwoven fabric to the surroundings. This longtube design can be a wrap around or serpentine on the surface of theapplication to be heated. The fuel 26 will boil 25 when the heatertemperature reaches its boiling point. The vaporized fuel 25 goes up thetube and condenses 32 on the vent line 2. Condensed fuel 32 is returnedto fuel in the tube by wicking into the tube liner 33.

FIG. 4 shows a cross-sectional view of cylindrical tubes, where themethanol fuel 49 and the air 35 are contained in parallel tubes 36 and38. The methanol fuel 49 is contained in one tube 36 and the air 35 ispumped through the adjacent tube 38 or tubes. The air tube 38 is made ofsilicone rubber or other polymers and is perforated with small pores 47to let air 35 flow through. The fuel tube 36 is made of silicone rubberand fuel selectively diffuses out through the silicone rubber to thesurrounding PBO felt or nonwoven fabric, which has been coated withcatalyst particles 39. The catalyst particles 39 are supported on aporous material of zeolite, alumina or activated carbon particles 43.These are then coated with sputter deposited films of Pt/Ru or Pt. Theactivated carbon 43 supported catalysts 42 can also be obtained fromEngelhard (Chemical Catalysts Group, 554 Engelhard Dr., Seneca, S.C.29678). The catalyst particles 39 are air brushed onto the PBO felt tube45. The PBO nonwoven fabric 45 with catalyst particles 39 are thenwetted and coated with air brushed solid polymer electrolyte DAIS 41 ina solvent, diluted with 1-propanol (Product number). The solid polymerelectrolyte 41 adheres the catalyst particles 39 to the PBO felt.Surrounding the catalyst coated PBO felt tube 45 is a second PBO felttube 44. This second PBO felt tube 44 acts as a thermal insulator fromthe outer skin tube 40. Vent holes 46 placed at the end of the skin tube40 are made of stainless steel or silicone rubber. In operation themethanol fuel 49 flows through the fuel tube 51 from a reservoir 37. Themethanol fuel 49 diffuses through the silicone rubber walls of the fueltube 36 to the catalyst particles 39. The methanol diffuses through thecoating 41 on the particles to the catalytic surface 42. Air is pumpedthrough the air tube 38 and through the vent holes in the air tube 38and bypass exit 48. Air diffuses through the coatings 41 to the Pt/Rucatalyst 42. The methanol and oxygen combust on the Pt/Ru surfaces 42and produce carbon dioxide and water. The carbon dioxide diffuses outthrough the catalyst coating 41 out to be carried away by the air flowand exit 46 or diffusing into the fuel 49 through the fuel tube wall 36.Carbon dioxide dissolved in the fuel 49 will be carried out with theflow of the fuel tube 36 to the reservoir tank 37, where it can vent outa vent hole 34 in the reservoir tank 37. Product water diffuses throughthe catalyst coating 41 from the catalytic surface 42 and is carried outthe air vent 42 with the airflow. Due to the selective permeability ofthe fuel tube 26 very little product water can back diffuse into thefuel 49. This keeps the fuel pure and its diffusion rate constantthrough the fuel tube wall 36. The heat generated from the catalyticburn conducts from the catalyst surfaces 42, through the coating 41,through the felts 45 and 44 to the fuel and air tube and the outer skinsurface 40. The heat produced can be delivered to the application eitherthrough conduction of the outer skin 40 or into the flowing fuel 49 andair 35 in the fuel 36 and air 38 tubes. The methanol fuel 49 can alsoboil 50 and remove heat. Alternatively heat can also be delivered by theflow of air out the bypass flow 48, the flow of exhaust gases throughthe vent 46, and by the condensing of fuel on the walls of the fuelreservoir 37.

In FIG. 5 a system of percolation circulation with heat exchangers and athermopile is shown. In this scheme the fuel reservoir is filled withmethanol fuel 76. The fuel is fed by gravity 75 through the supply tube70 to the bottom of the fuel membrane 58. The fuel 76 diffuses throughthe fuel membrane 58 to the PBO felt 77 coated with sputter depositedPt/Ru catalyst 56, and DAIS solid polymer electrolyte 57. Oxygendiffuses from the outside air 73 through the channels of the heatexchange aluminum block 72. The resulting combustion products of carbondioxide and water diffuse out through the channels of the aluminum block72. Some carbon dioxide diffuses though the fuel filter 58 into thefuel. The heat produced by the catalytic combustion at the Pt/Ru 56coated PBO felt 77 goes into the channeled aluminum block 72, throughthe fuel membrane 58 into the fuel 76. When the temperature of the fuelhits its boiling point the fuel boils and creates bubbles 68 in thefuel. The bubbles rise up to an aluminum heat exchanger 60. At the heatexchanger 60 the vaporized fuel 68 condenses 61 and delivers heat. Thecarbon dioxide bubbles 59 that are left after the fuel condensescontinue with the flow 63 of fuel to the reservoir tank 74. The carbondioxide 59 that does not stay in solution in the fuel vents through avent valve 64 on the vent line tube 62. The methanol that is carriedwith the venting gas is catalytically burned by a catalyst coated felt71 covering the outlet tube 62 and vent valve 64. The heat that travelsinto the channeled aluminum block 72 goes through a ceramic insulator 53into the thermopile 54. The thermopile consists of the Peltier junctionsformed by blocks of bismuth telluride alloy 54, metal conductors 52 andthe output leads 55 and 69. The heat flows through the thermopile outthrough a second ceramic insulator 66 and to a channeled aluminum heatexchanger 67. When the catalytic heater is running the thermopile willgenerate electrical power in addition to being able to supply heat.

In FIG. 6 the system shown uses the catalytic heater with heatexchangers, thermopile, pumped airflow, fuel control valves, andelectronic controls. This figure is an illustration of an application ofthe catalytic heater to be an electronic thermostat-controlled flowedair heater. In this scheme the fuel reservoir is filled with methanolfuel 81. The fuel is fed by gravity through a fuel tube 80 to the bottomof the fuel membrane 108 on the fuel tube 80. A shut off valve 100 isplaced near the inlet to the fuel membrane on the feed line. A secondvalve 79 is placed near the outlet to the fuel tank. Both valves couldbe electronically controlled but the most likely mode of operation is toelectrically shut just the upper valve 79 and stop the airflow thoughthe system. The lower shut off valve 100 could be a manual valve. Theheater 115, 106, 107 would continue to heat but drive the fuel away fromthe fuel membrane 108 with vaporized fuel. This would maintainpressure/temperature equilibrium with the heater so that the heaterwould remain idled with very little fuel. When the temperature dropsbelow the boiling point of the fuel, it would condense and refill thearea near the fuel membrane and subsequently start the heater repeatingthe cycle. Closing the shutoff valve 100 would stop the flow of fuel tothe heater which would continue to run until the vaporized fuel 99 andliquid fuel 110 is returned to the fuel reservoir 103 or combusted inthe catalytic burner 115, 106, 107. This would shut off the heatersystem. Pressure relief valves 104 and 114 could be placed on the fuelreservoir vent tube 82 and on either side of the upper valve 79 torelease excessive pressure and carbon dioxide gas. Relief valves 104,114 and vents can be incorporated as spring-loaded seals in cover caps.The open pressure for these relief valves sets the boiling point of themethanol fuel or other fuels. Different fuels can be used to set themaximum external temperature of the catalytic burner. By using heatpipes in parallel with a boiling fluid and a fixed quantity ofnon-boiling gas the upper external temperature of the catalytic burnercan also be set. To provide warmed airflow to the catalytic heater aduct 92 will be placed parallel to the outlet heat exchanger 85. Air 84is drawn through the heat exchanger 85 by a fan 89 to be preheatedbefore it arrives at the catalytic burner. The air goes through thecatalytic burner aluminum channels 116 and then the exhaust air 101passes back past the fuel tank 103. The exhaust air 101 cools as itpasses the fuel tank 103 and water a combustion product can be condensedout of the exhaust air 101 and collected in the exhaust tube 92. On theother side of a barrier 112 cold air 90 is drawn in through ducting 95to cool the aluminum heat exchanger 87 on the thermopile 113. The air 83is then pumped by a fan 97 to pass out through a heat exchanger 96 andout to the application. In operation the fuel 81 diffuses through thefuel membrane 108 to the coated PBO felt 115 coated with sputterdeposited Pt/Ru catalyst 106 and DAIS solid polymer electrolyte 107.Oxygen is drawn from the outside air with a fan 89 through the channelsof the heat exchange aluminum block 116. The air is preheated as itflows past the fuel reservoir and the heat exchangers with the outgoingair. The resulting combustion products of carbon dioxide and water arecarried with the flow out through the channels of the aluminum block116. Some of the product water can be condensed as the exhaust air 101is cooled and can be collected. Some of the product carbon dioxidediffuses though the fuel filter 108 into the fuel. The heat produced bythe catalytic combustion at the Pt/Ru 106 coated PBO felt 115 goes intothe channeled aluminum block 116 and through the fuel membrane 108 intothe fuel 81. When the temperature of the fuel hits its boiling point,the fuel boils and creates bubbles in the fuel 99. The bubbles in thefuel rise up to an aluminum heat exchanger 85. At the heat exchanger thevaporized fuel condenses and delivers heat. The carbon dioxide bubbles109 that are left after the fuel condenses 111 continue with the flow offuel to the reservoir tank 103. The carbon dioxide 109 that does notstay in solution in the fuel vents through a vent valve 104 on the ventline tube 82. The heat that travels into the channeled aluminum block116 goes through a ceramic insulator 93 into the thermopile 113. Thethermopile consists of Peltier junctions formed by blocks of bismuthtelluride alloy 105, metal conductors 117 and the output leads 165 and94. The heat flows through the thermopile out through a second ceramicinsulator 86 and to a channeled aluminum heat exchanger 87. When thecatalytic heater is running the thermopile will generate electricalpower in addition to being able to supply heat. The electrical powerfrom the thermopile can be used to run the fan motor 98, charge abattery and run the temperature control electronics for the thermostatand the electrically actuated valves. When the system is running thevalves 100 and 110 will open. Fuel will flow to the fuel membrane fromthe reservoir and the heater will turn on and rise in temperature. Invery cold conditions a resistance heater 88 using energy from thebatteries 122 shown in FIG. 7 the fuel membrane 108 and catalytic felt115, 106, 107 would be used to vaporize the fuel 81 and start thecatalytic combustion. When the temperature hits the boiling point of thefuel 81 the heat transfer will be increased by vaporization andcondensation. The thermopile 113 will produce sufficient power to runthe fan 98 motor and recharge the batteries 122 as shown in FIG. 7. Whensufficient heat is delivered to the application, the thermostat 118shown in FIG. 7 will close the second valve 79 and the fans 89, 97 willbe switched off. The vaporized fuel 99 will force the liquid fuel 81back away from the fuel membrane 108 back to the fuel reservoir 103. Thecatalytic heater 115, 106, 107 will go into a lower rate of combustionwith only oxygen diffusing to the heater through the inlet and outletducts and the fuel delivery rate reduced. A simplified version of atemperature regulated heater system could achieve temperature control bytemperature regulating the second valve 79 alone. In this simplifiedthermostatic system gas flow circulation is by convection air flow andboiling and condensation of the fuel. The electrical system could beeliminated by using valves that are differential metal or fluidexpansion valves (manufacturer). The heater devices as described can beused in a variety of applications with adaptations of components inapparel, blankets, machinery, dwellings, shipping containers, storagecontainers, odor generators, humidifiers, and insect attractants.

In FIG. 7 a schematic drawing of the electrical control system for theheater in FIG. 6 is shown. In this schematic the electrical output fromthe thermopiles 119 is fed through a diode 124 to charge a battery 122.The output of the battery 122 and the thermopile 119 is switched througha thermostat 118. The thermostat 118 is schematically represented forsimplicity as a bimetallic switch. There are a large number ofalternative thermostat mechanisms such as a thermistor and integratedelectronic controls. When the temperature on the thermostat 118 reachesthe desired set point the switch is closed and current runs the fan 121for the catalytic heaters and the delivered airflow. Anelectromechanical valve 120 is opened by the current flow and lets fuelflow to the diffusion membrane 108 to feed the catalytic heater 115,106, 107 fuel shown in FIG. 6. In this schematic FIG. 7 a secondbimetallic thermostat switch 171 is shown, that can be set to close whenthe temperature is lower than the needed temperature to start catalyticcombustion in the heater 115, 106, 107. This will divert current to aresistant coil heater 123 or catalyst electrolytic cell shown in FIG. 8.An alternative to the resistance heater is an ignition coil thatrepetitively sparks to ignite the fuel-air mixture over the catalystregion. This will initiate the catalytic combustion so that when thecatalytic heater reaches a self sustaining temperature the bimetallicthermostat switch 171 will open, stopping the electrically assistedcatalytic combustion. When the heater has delivered sufficient heat tobring the temperature to the desired set point of the load, thethermostat 171 opens the circuit turning off the fan 121. Theelectrically actuated valve is closed and the fuel supply to thediffusion membrane 108 is stopped. The catalytic heater 115, 106, 107will continue to run until it has used or cleared the fuel away from thediffusion membrane 108. The thermopile 119 will continue to charge thebattery 72 until the temperature of the catalytic heater drops and thevoltage of the thermopile falls bellow that of the battery. The diode124 will then prevent a discharge current flow back through thethermopile 119 from the battery 122.

In FIG. 8 an electrochemical combustion cell is shown. This deviceconsists of two electrodes 129, 126 formed by gold sputter coating PBOfelt 135, 133. Gas permeability into the electrodes is provided by openpores 140 in the felts 135, 133. Pt/Ru black or sputter coated Pt/Ru136, 134 is spray coated onto the PBO felt and a solid polymerelectrolyte DAIS 137, 125 in a 1-propanol solution is spray coated overthe Pt/Ru black 136, 134. A sheet of DAIS electrolyte 138 is insertedbetween the two electrodes 126, 129. A methanol fuel supply is providedto the cell by methanol diffusion through a selectively permeablemembrane 128 and a reservoir 130 of fuel 139 in close proximity to thecell. In operation, the methanol fuel 132 and air 131 diffuse to thesurface of the catalyst 136. A voltage potential is imposed across thecell through the electrodes 126, 129. Methanol and oxygen oxidize on thesurface of the catalyst 136. Different applied potentials across themembrane can be used to accelerate or impede the catalytic combustion.In this way, one can obtain a fine control over the catalyticperformance. On the surface of the catalyst 136, 134, protons areremoved from methanol and moved through the electrolyte coating 137through the separator electrolyte 138 and out to the second coatingelectrolyte 125. The proton movement through the electrolyte can alsoionically drag methanol fuel through the separator electrolyte 138increasing the delivery of fuel to be oxidized. In some situations withspecific concentrations of fuel on the source side 132 and the airsource side 131, the cell will run, as a fuel cell without externalpower needed to run current through the cell. The products of the cellare carbon dioxide and water, which diffuse out of the cell. Thiselectrochemical combustion cell can include the following five features:First, the electrical potential on the electrodes can clean thecatalysts. Second, the proton removal from the catalytic surfaceaccelerates the catalytic performance. Third, the electrical current canheat the catalyst regions through ohmic resistance. Fourth, theelectrochemical potentials on the catalysts and fuels can induceaccelerated catalytic performance that is very slow at roomtemperatures. Fifth, the different catalytic breakdown routes can occuron the catalysts at different potentials. Thus, a wider range of fuelsand fuel conditions could be handled with this mechanism compared tonon-polarized catalysis.

In FIG. 9 a mechanism of using the diffusion membrane to form a pressuresensitive valve to regulate the fuel and or oxygen delivery to catalyticcombustion is shown. In this arrangement of the invention the selectivediffusion membrane 158 can be thickened in spots 144 or have disks of animpermeable film 144 such as aluminum glued with silicone sealant orsputter coated onto the membrane 158 that correspond to apertures 153 ina plate 152. A catalytic felt 143 is placed over the aperture plate 152.Two air diffusion plates 148, 157 made of aluminum with offset apertures145, 149 are placed over the catalytic felt 143. The aperture plates148, 157 are glued 164, 150 with silicone sealant along the perimeterthrough the catalytic felt 143 to the aperture plate 162. The diffusionplates 148, 157 are spaced apart from each other by the thickness of theglue seal 164, 150. Both the fuel diffusion rate and oxygen diffusionrate can be controlled by either flexible sealing plates or non-alignedcompressible aperture plates and are show as an example of each in FIG.9. The diffusion of oxygen between the catalytic felt 143 and the firstflexible outer plate 148, on the oxygen pores 145 inlet side can beregulated by these same mechanisms as used with the fuel delivery. Withthe oxygen plates a second outer plate 157 and non-aligned apertures 149or sealing apertures are used. The oxygen diffusion is reduced when thefuel membrane 158 is pressed up against the fuel aperture plate 152; thecatalytic felt 143 and the outer plates 148 and 157. On the vent gas 141outlet 142 a pressure valve or flow-limiting valve 154 is placed. A fueltank is formed from aluminum 160. A silicone rubber fuel membrane 148 isglued with silicone sealant to the aluminum tank 160. Contained withinthe fuel manifold formed by the aluminum tank 160 and the siliconerubber membrane 148 is methanol fuel 151. In operation the fuel 151 isdelivered by diffusion through the membrane 158. Oxygen diffuses fromthe atmosphere to the catalytic felt 143 through the aperture plates 157and 148 to the catalytic felt 143 combusting the fuel and oxygen. Theheat from the combustion heats the fuel tank 160, boils the fuel 159 andheats the outer plate 157. Due to diffusion of gases such as carbondioxide and nitrogen into the fuel 151, the fuel tank 160 willpressurize. From this pressurization it bows the fuel membrane 158 andit subsequently presses it against the aperture plates 152, 148, 157 andthe catalytic felt 143, sealing off the diffusion of fuel and air to thecatalytic felt 143. This stops or reduces the production of heat fromthe catalyst combustor depending on the amount of diffusion reductionachieved by the fuel membrane 158 and the aperture plates 152, 148, 157.The combination of heat production and temperature of the heater can beregulated by the flow rate of the vent valve 154. The higher the flowrate allowed by the valve the higher the release of in-diffused gases orboiled fuel 159. The in-diffused gases are dependent upon thetemperature of the fuel membrane 158, and the boiling of the fuel 151.The in-diffusion of gases and the vaporized fuel create a net source ofgases in the fuel tank. By using a regulating valve 154 to vent gas 141on the outlet tube the fuel tank pressure is regulated, the fueldelivery is regulated through the membrane contact, and subsequently theheat production is regulated. The fuel vapors 141 released by theregulating valve are combusted by a catalyst-coated sleeve 146, 155, 147surrounding the vent line. Another mechanism of regulating catalyticcombustion occurs when the fuel membrane 158 presses up against theaperture plate 152, which can also cause the aperture plate 152 tocompress the catalytic felt 143 against the outer heat loss surfaces148, 157. This reduces the insulation of the catalytic combustion felt143, cools the catalytic combustion and reduces the reaction rates.

In FIG. 10 a cross-sectional view of the catalytic heater configuredwith a selectively permeable sealed fuel ampoule is shown. The fuelingof the catalytic heater can be done by ampoules of fuel that deliver thefuel by diffusion through the walls of the ampoule. In thisconfiguration of the catalytic heater, fuel ampoules 196 are formed bysealing a silicone rubber cylinder or bag containing methanol fuel 197with silicone sealant. These ampoules 196 can be stored in a methanolimpermeable container shown in FIG. 11 until use. A re-sealablemethanol-impermeable, thermally conductive container such as an aluminumcontainer 170, 192 that has a seal 180 around the rim is formed. Thecontainer is sealed from the outside (not shown) prior to use. There aremany possible mechanisms for the sealing of the container 170, 192 oneof which is a hinge and a clasp placed around the rim 190 compressing arim gasket 180. The aluminum container 170 has air in-diffusion holes inthe container wall 191. Within the methanol-impermeable, thermallyconductive container 170, 192 the fuel ampoule 196 and PBI felt 193 arecontained. The catalyzed felt 193 is formed by coating Pt/Ru on carbonsupport catalyst powder 194, and a protective permeable coating DAIS195, and is placed next to the air in-diffusion holes 191. In operation,the fuel ampoule 196 is placed in the container 170, 192 and clampedtogether. The methanol fuel diffuses to the catalyst 194 through theampoule wall 196 and the protective catalyst coating 195, while oxygendiffuses through the holes 191 in the aluminum case 192 and the catalystprotective coating 195 to the catalyst 194. The methanol fuel and oxygencatalytically combust on the catalyst 194 and the products of water andcarbon dioxide diffuse out through the protective coating, and thediffusion holes 191. Some of the carbon dioxide product can diffuse intothe fuel ampoule 196. It will come to equilibrium and diffuse back outof the ampoule since it is sealed. The fuel will boil 198 when thetemperature reaches its fuel boiling point. The fuel will condense 199with subsequent heat transfer to the aluminum container 170. When thefuel ampoule pressurizes, due to boiling of the fuel 198, the ampoule196 expands pressing against the catalytic felt 195,194,193 and pressingagainst the container wall 192. This increases the heat transfer ratefrom the catalytic felt and can reduce the air diffusion path to thecatalytic felt reducing the thermal output of the catalytic heater. Thusa self heat regulation mechanism is achieved in this device.

In FIG. 11 a cross-sectional view of a selectively permeable fuelampoule with fuel impermeable container is shown. The fuel ampoule isformed with methanol 182 inside a silicone rubber cylinder 183 andsealed with silicone rubber sealant. The fuel ampoule is then heatsealed inside a polyethylene bag 181. The silicone rubber walls have ahigh permeability to methanol fuel, while the polyethylene bag has a lowpermeability. The outer container 181 enables the fuel ampoule 183 to bestored until needed. When the fuel ampoule is needed the polyethylenebag 181 is torn open and the ampoule 183 is placed into the heaterdevice shown in FIG. 10. The more snug a fit to the silicone container,the more fuel can be stored and the lower the amount of dead volumewithin the polyethylene bag.

In FIG. 12 a cross-sectional view of the catalytic heater configuredwith a pump ampoule is shown. In this configuration the heater has anelastic fuel ampoule and the fuel diffusion region is elastic or thereis sufficient gas 201 in the tubing 200 to act as an elastic volume. Theheater system is formed by a thermoplastic rubber (Santopreneathermoplastic rubber, Advanced Elastomer Systems, 388 S. Main St., Ste60, Akron, Ohio 44311). The fuel bladder is formed by perimeter heatsealing with a thick wall membrane 218 and a thinner walled membrane220. The rubber is chosen to be impermeable to the methanol fuel andflexible. The fuel bladder 218 is filled with methanol fuel 219.Attached to the fuel bladder are inlet and outlet couplings that havespring loaded 227, 228 seals 221, 217. The fuel bladder 218 is coupledto the fuel hoses 200 and 212 with clamps 222, 216 or threadedcouplings. The couplings 221, 217 seal to the fuel hoses 200, 212 withVitona (Quality Gasket Company, 511 Gates Street, Philadelphia, Pa.19128) rubber seals 223, 215. The couplings are opened when hoses areclamped and the opening pins 224, 214 push the spring-loaded 228, 227valves open. Two one-way valves 225, 213 are placed in the fuel hoses200, 212. The closing pressure of these one-way valves 225, 213 can beset by the closing force such as a restoring spring 226, 229, andthereby set the minimum pressure needed to deliver fuel from the fuelbladder 218, 220. From the one-way valves 225, 213 a hose connects tothe fuel distribution bladder or capillary hoses 210. The fueldistribution bladder is made of capillary tubes of silicone rubber 210,230 with wall thickness of 0.5 mm to 0.025 mm thick (SiO flex tubing,Specialty Silicone Fabricators, 3077 Rollie Gates Drive, Paso Robles,Calif. 93446). Alternatively a silicone bladder 230 is made with a wallthickness ranging from 0.5 mm to 0.025 mm thick polyester reinforcedsilicone membrane 210 (Vulcanized Sheeting, Specialty SiliconeFabricators). A return fuel flow line 212 is connected between the fueldistribution bladder 210, 230 back to the second one way valve 213. Thefuel distribution bladder 210, 230 is placed in close proximity to thecatalytic heating felt formed by coating a PBO felt 206 with Pt/Ru black207 and overcoated with DAIS polymer electrolyte 208. The catalytic felt203 and the fuel distribution bladder 210, 230 are glued together withsilicone rubber sealant to form a combustion volume 209 within analuminum or silicone rubber box 204. Air diffusion holes 205 perforatethe aluminum box 204. In operation the fuel tank is connected to theheater system by making the two connections 215, 223. The fuel tanks canbe pre-filled ampoules with the pin connection that bursts and/or opensthe seals in the fuel connections. By pressing a finger on the fueldiaphragm 220 the fuel bladder 218 is pressurized and fuel 219 flowsthrough the first coupling 221, the first one way valve 225 and throughthe tube 200 to the fuel distribution bladder or capillary tube 230. Thesecond one way valve 213 is closed to flow back toward the fueldistribution bladder 230. The opening spring 226, 229 force on theone-way valves 225, 213 is set high enough to keep the valves closed toavoid gravitational hydraulic pressure causing a siphoning and the fuelto flow freely. When the finger pressure is relieved from the tankdiaphragm 220 the first one-way valve 225 is closed and the second valve213 opens when the pressure is low in the fuel bladder 218. This drawsfuel 219 and fuel vapor 211 out of the fuel distribution bladder 230.When the methanol fuel 219 is in the distribution bladder 230 the fueldiffuses out through the membrane 202 to catalyst felt volume 209. Themethanol fuel 219 diffuses to the surface of the catalyst coating 208and through to the catalyst surfaces 207. Oxygen simultaneously isdiffusing through the air inlet holes 205, into the catalyst-felt volume209 and through the catalyst coating 208 to the catalyst 207. The oxygenand methanol fuel catalytically combusts on the surface of the catalyst207. The products of water and carbon dioxide diffuse back through thecatalyst surface coating 208, into the catalyst felt volume and outthrough the air inlet holes 205. When the catalytic combustion deliverssufficient heat energy to cause the fuel to boil the fuel distributionbladder 210, 230 pressurizes. This pressurization causes the secondone-way valve 213 to open and the methanol vapor 211 and liquid 219flows into the fuel bladder 218. The methanol vapor will condense in thefuel bladder 218. The pressurization of the fuel distribution bladderfrom vaporized fuel and in diffusion of gasses due to the boiling of thefuel also results in the diffusion membrane 210 bulging and compressingthe catalytic felt 203 against the container wall 204. This increasesthe thermal conductivity from the catalytic sites 207 to the outside airand cooling the catalyst 207. By compressing the catalytic felt 203against the wall, the space available for diffusion of oxygen alsodecreases and the oxygen diffusion to the catalytic sites 203 isreduced, thereby reducing the rate of catalytic combustion. Thecatalytic sites cool and the methanol fuel 211 cools thereby giving thiscatalytic combustion system temperature feedback control. The pumping offuel can be used as a feature in applications, such as in apparel wherethe user presses the fuel tank bladder 220 to receive a pulse of heat.This allows the user to control the time and amount of heating.

Essential features:1. Fuel delivered though a selectively permeable membrane.2. The selectively permeable membrane allows fuel to be delivered andnot back diluted by the product water.3. A selectively permeable membrane to allow oxygen and with a reducedpermeability to fuel to retain fuel.4. The carbon dioxide and other gasses diffuse into the membrane andvent and circulate through the fuel with the fuel boiling.5. A catalyst dispersed over a porous material.6. A fuel and oxidizer permeable protective coating over the catalyst.7. A selectively permeable coating over the catalyst.8. A fuel retaining coating over the catalyst.9. A coating over the catalyst that enhances the performance of thecatalyst.10. A coating over the catalyst that is electrolytic and or acidic orbasic.11. The fuel vaporization and departure from the membrane to catalystreaction area to act as a thermostat of upper temperature limitmechanism.12. Valving or flow restrictions to regulate the boiling or fuel fillingto regulate temperature of heating rates.13. Using fuel additives such as water or other hydrocarbon fuel withdifferent boiling points to adjust the catalytic burner temperatures.14. Using the fuel vaporization and condensation as a heat pipe heatexchanger.15. The onset of boiling of the fuel to keep the reaction areatemperature elevated.16. To incorporate thermopiles to extract electrical energy from theheater and transfer heat.17. To use heat exchangers to warm up air going to the heater andexchange heat with the load.18. Extracting water from the condensation of the exhaust from theheater.19. Use a selectively permeable membrane to regulate the oxidizer to thecatalyst reaction area.20. Use of stoma devices to thermally regulate the oxidizer gas to thecatalyst area.21. Use of fans or pumps to regulate the fuel or oxidizer delivery tothe catalyst area or heat exchange.22. The use of electrochemical catalysis to enhance the performance.23. Use of electric heating to start the catalytic heater.24. Use of passive mechanical controls and pressurization of the fuel tocontrol the heat output.25. Use of a wick to distribute fuel over the selectively permeablemembranes.26. Use of the heater on many systems, apparel, blankets, machinery,dwellings, shipping containers, storage containers insect attractants,humidifiers, and perfume generators.

While the invention has been described with reference to specificembodiments, modifications and variations of the invention may beconstructed without departing from the scope of the invention, which isdefined in the following claims.

1. A heat-generating device comprising a fuel source, a fuel deliveryconnected to the fuel source, a catalyst dispersed over a poroussubstrate, the catalyst being in diffusive contact with an oxidizinggas, and a selectively permeable membrane for selectively deliveringfuel to the catalyst. 2-17. (canceled)
 18. The device of claim 1,further comprising electrical temperature responsive devices forcontrolling fuel flow.
 19. The device of claim 1, further comprisingheat exchangers for transferring heat from the device to the fuel. 20.The device of claim 1, further comprising heat exchangers for heatingair going to the catalyst.
 21. The device of claim 1, further comprisingheat pipes for transferring heat from the device, regulatingtemperatures in the device, and transferring heat to fluids and solids.22. The device of claim 1, further comprising fuel additives forregulating temperatures and heat production rates.
 23. The device ofclaim 1, further comprising mixtures of fuels for regulatingtemperatures and heat production rates.
 24. The device of claim 1,further comprising thermoelectric devices for extracting electricalenergy.
 25. The device of claim 24, further comprising a delivery systemfor delivering electrical energy to batteries, motors, and electronicdevices.
 26. The device of claim 1, further comprising water producedfrom fuel combustion.
 27. The device of claim 26, wherein the device isadapted for condensation of the water and comprising an exhaust forcollecting the water after condensation.
 28. The device of claim 1,wherein the selectively permeable membrane regulates delivery of oxidantto the catalyst.
 29. The device of claim 1, further comprising a wickfor distributing liquid fuel over a surface of selectively permeablemembrane.
 30. The device of claim 1, wherein the selectively permeablemembrane is selectively permeable to gases and fuel boiling in thedevice and wherein the membrane uses the selective permeability toaspirate, circulate, or prevent motion of the fuel.
 31. The device ofclaim 1, wherein the selectively permeable membranes are capable ofchanging diffusion rates with changes in temperature.
 32. The device ofclaim 1, wherein the selectively permeable membranes change diffusionrates with temperature changes for regulating temperature of the device.33. The device of claim 1, wherein the selectively permeable membraneschange diffusion rates with temperature changes for regulating heatoutput.
 34. The device of claim 1, wherein the selectively permeablemembrane uses pressurization and subsequent effect on fuel containmentat elevated temperatures for limiting delivery of the fuel or oxidizerto catalytic reaction sites in the device.
 35. The device of claim 1,further comprising fans or pumps for regulating delivery of fuel oroxidant to an area of the catalyst.
 36. The device of claim 1, furthercomprising fans or pumps for regulating heat exchange in an area of thecatalyst.
 37. The device of claim 1, further comprising an electricheater for initiating optimal conditions to operate the device.
 38. Thedevice of claim 1, further comprising an ignition system for ignitingfuels and air and for heating the catalyst.
 39. The device of claim 1,further comprising a proton-conducting material for supporting thecatalyst, at least two electrodes on either side of theproton-conducting material, and a power source connected to theelectrodes for providing a voltage.
 40. The device of claim 39, furthercomprising influencing catalytic combustion rates by applying thevoltage across the proton-conducting material.
 41. The device of claim1, further comprising a receiver for receiving the device.
 42. Thedevice of claim 41, wherein the receiver is selected from the groupconsisting of apparel, blankets, machinery, dwellings, shippingcontainers, storage containers, odorants, humidifiers, insectattractants, and combinations thereof.
 43. The device of claim 1,further comprising means for pumping fuel towards an area of thecatalyst.
 44. The device of claim 1, further comprising a fuel ampoulehaving fuel-permeable walls for holding and releasing the fuel.
 45. Thedevice of claim 44, further comprising an impermeable material forholding the ampoule for preventing leakage of the fuel prior to use. 46.A heat generating apparatus comprising a heat generating device, fuelfrom a fuel supply, a selectively permeable membrane for selectivelydelivering the fuel, a catalyst and a means to deliver an oxidant orair.
 47. The apparatus of claim 46, wherein the device is a portablecatalytic combustion heater.
 48. The apparatus of claim 47, furthercomprising a fuel and air delivery for supplying the fuel and theoxidant or air to the catalyst and for flameless combustion of the fuelfor releasing heat.
 49. The apparatus of claim 48, wherein the fuel is aliquid fuel passing through the selectively permeable membrane such thatfuel vapor exits the membrane and is fed to the catalyst.
 50. Theapparatus of claim 46, further comprising porous supports for supportingthe membrane.
 51. The apparatus of claim 50, further comprising meansfor enhancing and diminishing a catalytic rate of combustion and forcontrolling a heat output.
 52. The apparatus of claim 46, furthercomprising a receiver for receiving the device.
 53. The apparatus ofclaim 52, wherein the receiver is selected from the group consisting ofheat apparel, blankets, food, dwellings, containers, machinery, insectattractants, humidifiers, perfume generators, and combinations thereof.54. The apparatus of claim 46, wherein the fuel is delivered through theselectively permeable membrane.
 55. The apparatus of claim 54, whereinthe selectively permeable membrane allows fuel to be deliveredtherethrough and prevents back dilution with byproducts of combustion.56. The apparatus of claim 55, wherein the byproducts comprise water.57. The apparatus of claim 54, wherein the selectively permeablemembrane allows oxygen therethrough and comprises reduced permeabilityto retain the fuel.
 58. The apparatus of claim 54, wherein carbondioxide and other gasses diffuse into the selectively permeable membraneand vent and circulate through the fuel with the fuel boiling in thedevice.
 59. The apparatus of claim 46, further comprising a porousmaterial substrate, wherein the catalyst is dispersed over the porousmaterial substrate.
 60. The apparatus of claim 59, wherein theselectively permeable membrane is a fuel and oxidizer permeableprotective coating over the catalyst.
 61. The apparatus of claim 59,wherein the selectively permeable membrane is a selectively permeablecoating over the catalyst.
 62. The apparatus of claim 59, furthercomprising a fuel retaining coating over the catalyst.
 63. The apparatusof claim 59, further comprising a coating over the catalyst forenhancing a performance of the catalyst.
 64. The apparatus of claim 59,further comprising a coating over the catalyst, wherein the coating isselected from the group consisting of electrolytic, acidic, basicsubstances, and combinations thereof.
 65. The apparatus of claim 59,wherein vapors of the fuel depart from the selectively permeablemembrane to reaction areas of the catalyst and form a thermostatproviding an upper temperature limit for catalytic reactions.
 66. Theapparatus of claim 65, further comprising valves or flow restrictors forregulating boiling of the fuel and filling of the fuel and forregulating temperature and/or heating rates.
 67. The apparatus of claim59, further comprising fuel additives for adjusting catalytic burningtemperatures.
 68. The apparatus of claim 59, further comprising fueladditives.
 69. The apparatus of claim 68, wherein the fuel additivesinclude hydrocarbons with different boiling points.
 70. The apparatus ofclaim 68, wherein the fuel additives include water.
 71. The apparatus ofclaim 46, further comprising a heat exchanger formed by vaporization andcondensation of the fuel.
 72. The apparatus of claim 71, wherein theheat exchanger is a heat pipe.
 73. The apparatus of claim 46, furthercomprising a temperature elevation formed by a boiling of the fuel formaintaining a reaction area temperature elevated.
 74. The apparatus ofclaim 46, further comprising thermopiles for extracting electricalenergy from the heating device and for transferring heat in the heatingdevice.
 75. The apparatus of claim 71, wherein the heat exchangers warmup air going to the heating device and exchange heat in the heatingdevice.
 76. The apparatus of claim 46, further comprising an exhaust andan extractor for extracting water formed from a condensation of theexhaust from the heating device.
 77. The apparatus of claim 46, whereinthe selectively permeable membrane regulates flow of air or oxidant to acatalytic reaction area.
 78. The apparatus of claim 77, furthercomprising stoma for thermally regulating the air or oxidant to thereaction area.
 79. The apparatus of claim 78, further comprising fans orpumps for regulating delivery of the fuel and/or air or oxidant to thereaction area.
 80. The apparatus of claim 78, further comprising fans orpumps for regulating heat exchange in the reaction area.
 81. Theapparatus of claim 78, wherein the catalyst causes electrochemicalcatalysis for enhancing a performance of the catalyst.
 82. The apparatusof claim 46, further comprising a power source for electrical heating toturn on the heating device.
 83. The apparatus of claim 46, furthercomprising controls for pressurization of the fuel to control heatoutput.
 84. The apparatus of claim 83, wherein the controls are passivemechanical controls.
 85. The apparatus of claim 46, further comprising awick for distributing fuel over the selectively permeable membrane. 86.The apparatus of claim 85, further comprising a receiver for holding theheating device.
 87. The apparatus of claim 86, wherein the receiver isselected from the group consisting of apparel, blankets, machinery,dwellings, shipping containers, storage containers insect attractants,humidifiers, perfume generators, and combinations thereof.